AlF3对冰晶石熔盐体系结构与性质影响的分子动力学模拟研究  

Molecular Dynamics Simulation of the Effect of AlF_3 on Structure and Properties of Cryolite Melts

作　　者：田国才[1] 王永志[1] 

机构地区：[1]昆明理工大学省部共建复杂有色金属资源清洁利用国家重点实验室,冶金与能源工程学院,云南昆明650093

出　　处：《昆明理工大学学报（自然科学版）》2015年第3期1-8,共8页Journal of Kunming University of Science and Technology(Natural Science)

基　　金：国家自然科学基金项目(50904031,51264021);云南省中青年学术技术带头人后备人才项目(2011HR013)

摘　　要：采用分子动力学方法研究了1283 K、0.1 MPa时不同摩尔分数的Al F3对冰晶石熔盐体系结构与性质的影响.获得了体系的密度、径向分布函数、配位数、扩散系数、电导率和粘度.结果显示熔体的结构比较疏松,熔体中Al主要的离子集团形式为Al F3-6八面体,且熔体中形成了Al-F-Al氟桥结构.随着Al F3含量的增加,Al3+-F-、F--F-间的配位数均增大,各离子的扩散系数减小,体系的电导率不断减小,粘度先增大后减小.研究工作揭示了Al F3对冰晶石熔盐体系中离子的存在形式、迁移性、离子间相互作用和扩散机制的影响,对铝电解生产具有重要的指导意义.The effect of AlF3 on the structure and properties of cryolite melts are studied by molecular dynamics simulations at 1283 K and 0. 1 MPa. The radial distribution functions,coordination numbers,diffusion coefficients,conductivities and viscosities of the systems are obtained. It is shown that the melts have fairly loose structure; that Al- F- Al fluorine bridge is formed in the melts; and that the main ion group is AlF3-6octahedral. The coordination numbers of Al^3＋- F^-and F^-- F^-increase with increasing AlF3 mole fraction. As the AlF3 mole fraction increases,the diffusion coefficient and the conductivity decrease,and the viscosity increases first and then decreases. The effects of AlF3 on the ionic forms,mobility,ionic interactions,and diffusion mechanisms of cryolite melts are revealed,which is important for the production of aluminum by electrolysis.

关 键 词：ALF3 冰晶石 铝电解 熔盐 分子动力学模拟 

分 类 号：TF01[冶金工程—冶金物理化学] O642[理学—物理化学]